Rockies’ prospect Nolan Arenado won’t get September call-up

Don’t look for third base prospect Nolan Arenado to get called up when the Rockies expanded their September roster beginning Saturday. Later in the month? Maybe, but not very likely.

The Rockies remain very high on Arenado, even though he’s hitting just .281 at Double-A Tulsa. After scuffling earlier this season, Arenado’s shown increased maturity and played well of late. He hasn’t kicked down the door to get to the majors, but the club is excited to see what the 21-year-old can do at the big-league level.

But right now is not the right time. Here are the Rockies’reasons:

* To bring up Arenado now, the Rockies would have to add him to their 40-man roster. That means another player would have to come off the 40-man roster, if not now, then later when winter rosters must be set. The Rockies currently have 39 players on their 40-man roster.

Players taken off the 40-man could potentially be lost during the Rule 5 draft at December’s winter meetings.

* Adding Arenado to the 40-man starts the clock ticking on his big-league arbitration.

* Arenado’s Drillers are in the playoffs and begin play Wednesday, and he’s a central part of that team.

* With so many young position players thriving with the Rockies right now, it doesn’t make sense to bring Arenado up, thus taking away playing time from other young players.

* For now, the Rockies want Arenado to continue getting better as a baseball player and not worry about the expectations that come with a big-league promotion.

Manager Jim Tracy did announce today that first baseman/pinch hitter Jason Giambi and right-hander Guillermo Moscoso will rejoin the team Saturday. Both players, of course, are already on the 40-man.

In other news, Troy Tulowitzki is scheduled to play seven innings at shortstop for Triple-A Colorado Springs Friday night. He will return to Denver on Saturday to be checked out. Though Tulo wants to play for the Rockies again this season, there is no set timetable for his return.